Exercise machines may use electrical power to operate. For example, a treadmill may use electrical power to operate the treadmill belt that a user walks/runs on. In various situations, the speed that a motor can operate at may be limited by the electrical power that is available. Exercise machines are typically coupled to a mains power supply (through an electrical outlet, for example). Typical commercial wiring provides alternating current (AC) with multiple hot legs and/or higher current circuits. In contrast, typical residential wiring provides AC with a single hot leg (at 120 volts, for example) in a 15 Ampere (amp) maximum circuit. Therefore, a typical residential wiring circuit provides a maximum of 1800 watts.
Some exercise machines may be limited by the 1800 watt limit of the typical residential wiring circuit. For example, the belt speed of known treadmills (e.g., direct current (DC) motor based treadmills) may be limited by the power restrictions of the residential wiring circuit. For instance, the maximum belt speed of known treadmills using residential wiring is 12 miles per hour (mph). In general, known DC motor based treadmills rectify the 120 volt AC power from the residential circuit into DC power that may be supplied to the DC motor. In one example, the DC power may be at 160 volts DC which corresponds to an efficiency of about 65% to 75% and a maximum treadmill belt speed (given the power restrictions of the residential wiring circuit) of about 12 mph. However, in various situations a 12 mph belt speed may be insufficient. For example, a user may desire to run faster than 12 mph.